Directions1. Place dry lentils in a colander or sieve and rinse with cool water. Drain.2. Combine rinsed lentils and water in a pot. Bring water to a boil and then reduce to a simmer. Cook covered until tender, stirring occasionally. For brown, French, or yellow lentils, allow 25-30 minutes for cooking. For red lentils, allow 5-10 minutes. Drain any excess cooking liquid. Allow to cool. 3. While lentils are cooking and cooling, combine Dijon mustard, cider vinegar, shallots, oil, and salt to make a dressing. 4. Toss together cooled lentils, apple, spinach, and walnuts. Drizzle with dressing and toss gently to coat. Serve chilled.